Home appliance



Feb. 13, 1962 E. F. HUBACKER ETAL 3,020,733

HOME APPLIANCE 3 Sheets-Sheet 1 Filed April 20, 1959 INVENTORSI EARL EHUBACKER JOHN E KRUG 7 J flai w ATI'Ys Feb. 13, 1962 E. F. HUBACKER ETAL3,020,733

HOME APPLIANCE Filed April 20, 1959 5 heets-Sheet 2 INVENTORSI EARL F.HUBACKER JOHN E. KRUG ATT'YS Feb. 13, 1962 E. F. HUBACKER ETAL 3,020,733

HOME APPLIANCE Filed April 20, 1959 3 Sheets-Sheet 3 FIG?) INVENTORSIEARL F. HUBACKER ATT'YS United States Patent ()filice 3,020,733 PatentedFeb. 13, 1962 This invention relates to a refrigerating apparatus and tomethods of cooling.

The refrigerating apparatus of this invention provides separate chambersas in a domestic refrigerator of the type in which one chamber is usedfor storing fresh foods at above freezing temperatures and anotherchamber is used for storing frozen foods at below freezing temperatures.In the apparatus of this invention means are provided for forcingseparate air streams through the two chambers, means for interminglingthe separate streams, means for dividing the intermingled air into thetwo separate streams and means for cooling the low temperature chamberair stream only after the separation of the air into the two streams.With this arrangement the air stream through the storage or relativelyhigher temperature chamber is cooled primarily by the intermingling ofthe two streams although air cooling means may be provided as desired inthe area of intermingling.

One of the features of this invention is to provide an improved methodof cooling first and second chambers comprisin simultaneouslycirclulating air through said chambers in first and second streams,mingling the air streams at a common juncture followed by separating theair into said first and second streams, and cooling one of said streamsonly subsequent to its passage through said juncture.

Another feature of the invention is to provide an improved method ofcooling first and second chambers comprising simultaneously circulatingair through said chambers in first and second streams, isolating saidfirst stream from the first chamber prior to passing the stream into thefirst chamber, mingling the air streams at a common juncture followed byseparating the air into said first and second streams, cooling saidfirst stream during said isolation and cooling said mingled streams atsaid common juncture.

A further feature of the invention is to provide an improvedrefrigerating apparatus comprising mean forma relatively low temperaturefirst chamber, means forming a relatively high temperature secondchamber, means forming a mixing chamber, means for circulating a firstair stream through the first chamber and a second air stream through thesecond chamber, means directing both air streams through the mixingchamber for intermingling therein, and means for cooling said first airstream only at a point downstream from said mixing chamber.

Yet another feature of the invention is to provide an improvedrefrigerating apparatus comprising means forming a relatively lowtemperature first chamber, means forming a relatively high temperaturesecond chamber, means forming a mixing chamber having a first inletcommunicating with the first chamber and a second inlet communicatingwith the second chamber, a blower adjacent said mixing chamber having aninlet communieating therewith, a first outlet and a second outlet, meansforming a first air passage communicating with said first outlet andemptying into the first chamber, means forming a second air passageadjacent said second chamber communicating with said second outlet,means forming an outlet from the second passage to the second chamber,the blower thereby circulating air in a first stream through the firstpassage, first chamber and mixing chamber and i in a second streamthrough the second passage, second chamber and mixing chamber, andcooling means for the air in said first passage.

Another feature is to provide an improved refrigerating apparatuscomprising means forming a relatively low temperature first chamber,means forming a relatively high temperature second chamber, meansforming a mixing chamber having a first inlet communicating with thefirst chamber and a second inlet communicating with the second chamber,a blower adjacent said mixing chamber having an inlet communicatingtherewith, a first outlet and a second outlet, means forming a first airpassage communicating with said first outlet and emptying into the firstchamber, means forming a second air passage adjacent said second chambercommunicating with said second outlet, means forming a plurality ofoutlets from the second passage to the second chamber, means in saidsecond chamber for maintaining the air fiow from said plurality ofoutlets substantially parallel, the blower thereby circulating air in afirst stream through the first passage, first chamber and mixing chamberand in a second stream through the second passage, second chamber andmixing chamber, a first refrigerant evaporator means in said firstpassage, and a second refrigerant evaporator means in said mixingchamber.

Other features and advantages of the invention will be apparent from thefollowing description of one embodiment of the invention considered inconjunction with the accompanying drawings. Of the drawings:

FIGURE 1 is a semi-diagrammatic vertical sectional view through anembodiment of the invention.

FIGURE 2 is an enlarged sectional detail view of the embodiment ofFIGURE 1.

FIGURE 3 is a sectional elevational view taken substantially along theline 33 of FIGURE 1. 7

FIGURE 4 is a sectional elevational view partially broken away forclarity of illustration and taken substantially along line 4-4 of FIGURE2.

FIGURE 5 is a wiring diagram of the embodiment of the preceding figures.

The refrigerator of this invention comprises a lower relatively lowtemperature first chamber 10 for storing frozen foods and the like and arelatively high temperature second chamber 11 for storing fresh foodsand the like. The refrigerator is formed of the customary insulatedwalls including top wall 12, a rear wall 13 and a bottom wall 14 and isprovided with a pair of access doors to the first and second chamberswith these doors being shown diagrammatically at 15 and 16. It is ofcourse to be understood that any type door closures desired may be usedincluding those of the customary type provided with the usual sealinggaskets. The doors may contain inner shelves of the customary typeadapted to hold and support articles. The two chambers 10 and 11 areseparated from each other by an insulated transverse wall 17 sealed atthe front as by a gasket 18.

At the rear of the upper chamber 11 there is provided an upwardlyextending air passage, or flow chamber 19, extending upwardly from ablower 20 which is operated by an electric motor 21 located in theinsulation of .the rear wall 13. Extending downwardly from the blower 2dat the rear of the lower chamber 10 is a second air passage, or flowchamber, 22 defined by a rear wall 23 and a forward evaporator coverplate 24. Between this rear wall 23 and coverplate 24 there is located arefrigerant evaporator 25 of customary construction. In order to providefor exit of air at the bottom of the cover plate 24 this plate isprovided with a plurality of bottom louvers 26. j

A bottom plate 27 is provided at the bottom of the evaporator 25 andthis plate is provided with an opening communicating with a downwardextending drain pipe ZS 3 upturned at its lower end as indicated at 29to provide a trap. This en of the drain pipe spills into a bottom pan 30so that condensate from the evaporator when the evaporator andassociated structure is defrosted will flow down through the pipe 23 andinto the pan for evaporation therefrom in the customary manner.

The upper end 31 of the cover plate 24 is angled to extend upwardly andforwardly toward but spaced from the rear of the transverse insulatedwall 17. This upper end 31 is spaced from the blower 20 to provide achamber 32 in front of the blower and behind the end 31. Mounted on thecover plate end 31 within the chamber 32 is a refrigerant accumulator 33which is interconnected in the refrigerant circuit in the usual mannerby means including the tube 34.

The bottom of the upper refrigerated chamber 11 is defined by a bottomplate 35 which forms the upper surface of the insulated wall 17. Thisbottom plate 35 is provided with a plurality of apertures 36 at its rearto provide communication between the chamber 32 and the second chamber11.

The upwardly extending air passage 19 is defined at its rear by thefront surface 37 of the rear wall 13 and a forwardly spaced upwardlyextending wall 38. This wall 38 extends upwardly but terminates short ofthe upper end of surface wall 37 to provide a relatively large opening39 at the top of chamber 11. The bottom plate 35 at the rear of theapertures 36 extends upwardly in front of the wall 38 and is attachedthereto. This front wall portion 40 is closely spaced to the wall 38 andis attached thereto. The walls 38 and 40 contain aligned apertures toform air flow openings 41.

The evaporator cover plate 24 is provided with vertical ribs 42 at theupper end 31 and the plate is provided with side flanges 43 and 44 forattachment to the side plates 45 that form the sides of the lowerchamber 10. Between the ribs 42 are provided spaced sets of inwardlyextending deformations 46 which in conjunction with the ribs 42 serve tostrengthen the upper end 31.

As is shown most clearly in FIGURE 2 the bottom end 47 of the wall 38extends forwardly and downwardly in front of the blower 20 and isprovided with an inwardly extending cylindrical flange 48 at theentrance to the blower 20. In front of this flange 48 is provided abaflle plate 49 which is attached to the rear of the plate 35 andextends downwardly in front of the flange 48 and then slopes forwardlyand downwardly to the bottom of the upper end 31 of the cover plate 24.The lower end of this plate 49 is attached to the cover plate as by aplurality of screws 50. From the point of attachment of the lower end ofthe plate 49 the plate is bent upwardly and rearwardly to provide a lip51 which has an edge 52 above the point of attachment at the screws 50.The portion of the plate 49 above the screws but beneath this upper end52 is provided with a series of horizontally aligned openings asindicated at 53 in FIGURE 2.

The construction of the air passages 19 and 22 is shown most clearly inFIGURE 4. These air passages are preferably formed of rigid plastic andthe motor 21 is attached to the rear side of the rear wall 37 as shownin FIGURE 2. The rearward duct housing 37 is shaped to divide the airleaving the blower 20 so that the proper ratios of air are delivered tothe lower chamber 10 and the upper chamber 11. Thus beginning at a pointto the left of the blower 20 in FIGURE 4 and above the center linethereof there is provided a substantially horizontal partition 54extending outwardly and cur'ving downwardly in a long radius ofcurvature.

On the other side of the blower 20 approximately the reverse conditionis true. Thus beginning at the opposite side another partition 55 curvesupwardly and toward the blower 20 to within the righthand edge of theair passage 19 and then is reversed and extends upwardly and outwardlyas indicated at 56 to join the sidewall 57 forming the lateral sides ofthe passage 19.

The blower 20 is of the conventional type having inclined blades 58.However the blower is rotated in a direction opposite to its normaldirection of rotation as indicated by the arrow 59 in FIGURE 4 so thatthe blades 58 push the air outwardly in a generally radial direc' tionas illustrated diagrammatically by the air flow arrows in FIGURE 4. Thusthere is a good distribution of air throughout the upper air passage 19and the lower air passage 60 at the bottom of the wall 37. This airpassage 60 of course empties into passage 22 for air flow and heattransfer relationship to the evaporator 25.

The above described arrangement of blower and air passages provides thedesired distribution of air into the two chambers 10 and 11. In thepreferred construction a major portion or more than 50% of the air flowis directed downwardly through the air passage 22 over the evaporator 25and through the lower low temperature chamber 10. In one embodiment ofthe invention this percentage was 60% of the total air flow. Theremainder of the air then of course is directed upwardly through thepassage 19 and through the upper relatively higher temperature chamber11. The air from this upper chamber 11 returns through the spacedopenings 36 into the mixing chamber 32 while the air from the lowerchamber 10 flows in the passage 61 between the upper end 31 of the plate24 and the rear of the insulated wall 17 into the mixing chamber 32.

The air from the passage 19 is directed into the upper refrigeratorchamber 11 through the upper opening 39 and intermediate openings '41.Immediately beneath the upper opening 39 is a solid sealed shelf 62which is sealingly supported at the supports 63 and extends toward butshort of the door 16. This first shelf 62 is above the openings 41 butbeneath the opening 39. Beneath the openings 41 there is providedanother similar solid sealed shelf 64 similarly supported and alsoextending toward but short of the door 16. This shelf 64 may also serveas the top for the crisper pans 65. Between the two solid shelves 62 and64 may be provided open type wire shelves of conventional constructionor similar supports that will not interfere with air flow. The solidupper shelf 62 not only provides storage space but also provides a space66 of minimum temperature (which may be about 33 F.) and also directsthe air forwardly. The openings 41 provide the correct amount of air inthe center area 67 of the chamber 11. These two streams of air flow aredirected forwardly and downwardly and then pass rearwardly along thesides of and beneath the crisper pan 65 to flow through the openings 36into the mixing chamber 32. These openings 36 are preferably long andnarrow. In the mixing chamber the air passes over and around theaccumulator 33 before entering the blower inlet in the bafile plate 49.This provides the additional function of depositing moisture containedin the air in the mixing chamber onto the accumulator surface so thatfrosting of the blower wheel is eliminated.

This mixing of air from the chambers 10 and 11 in the mixing chamber 32provides the proper temperature of air for the upper storage chamber 11as is indicated by the following example of one embodiment of theinvention.

Thus in this embodiment the air leaving the evaporator bottom throughthe louvered openings 26 was approximately -10 F. The air leaving thefreezer chamber 10 through the opening 61 was approximately 0 F. The airentering the upper passage 19 from blower 20 was approximately l2-l5 F.and the air leaving the upper chamber 11 through the openings 36 wasapproximately 35 F. Thus air at approximately 35 F. was mixed in themixing chamber 32 with air at approximately 0 F. and a portion of theresulting air was then directed upwardly through the passage 19 toprovide for cooling the upper or fresh food storage chamber 11 while themajor portion of the air was directed downwardly over the evaporatorwhere it was again cooled to approximately 10 F. Some cooling is alsoachieved in the mixing chamber 32 by air flow over and around theaccumulator 33.

FIGURE illustrates an electrical circuit for the operation of the entireapparatus. The ordinary compressor 69 is connected through switch 7t} toone side of the source of electricity which is a line 71. This switch 78may be a conventional thermostatic control switch with its capillarybulb mounted as indicated at 72 to the top of the accumulator 33. Theother side of the cornpressor 69 is connected to contact 72 of theswitch 73, the arm 74 of which is connected to the other side of thesource of electric power which is the line 75. The arm 74 of switch 73is normally held to the contact 72' by a defrost timing clock '76 whichis connected between the electric lines 71 and 75. Thus the clock runscontinuously. At periodic intervals which may be every 12 hours thedefrost clock mechanism is arranged to break the compressor circuit byturning the arm 74 of the switch 73 to engage a contact 77. Since thearm 78 of a switch 79 is normally held to engage a contact 80 thisplaces the heater wire 31 directly across the lines 71 and 75.

When all the frost on the evaporator surfaces has been melted, switch 7%is caused to reverse its contacts. This switch is a bimetal type whichalso is mounted on the accumulator 33 because it is normally the lastpoint to be free of frost. When the accumulator has reached an abovefreezing temperature showing that it is substantially free of frost,switch arm 79 closes on contact 82 to start the operation of thecompressor 69. This arrangement which is conventional in refrigerationcircuits starts the operation of the compressor even though the arm 74of the defrost switch 73 may still be in engagement with the contact 77.This arrangement assures that the defrost heating cycle is terminated bytemperature after all ice from condensed moisture has been removed,rather than having the defrost cycle terminated by time.

The fan motor 21 is arranged .in series with a switch 83 so that undernormal operating conditions the fan motor runs at all times that thecompressor is running. After a defrost cycle, when the evaporatorsurfaces have been warmed to remove accumulated frost, it is preferablenot to begin operation of the fan and circulation of air immediately. Inorder to provide for this operation the switch 83 is preferably ab'imetal switch and is preferably mounted on the uppermost point 84 ofthe tube 34 that connects the outlet of the evaporator 25 to the inletof the accumulator 33. Thus after a defrost cycle the blower 29 is notenergized until the refrigerant reaches the inlet to the accumulator.This provides for the proper temperature in the evaporator so that onlycold air is circulated.

The defrost heater wire 81 extends along the evaporator 25 in passes inthe customary manner to melt frost deposited thereon. In addition twopasses of the heater wire (FIG. 2) are arranged on the upper end 31 ofthe cover plate 24 adjacent the accumulator 33 and one .pass is arrangedadjacent the openings 53 to quickly melt the ice frozen in the openings.During the defrost operation frost melts from the accumulator 33 andfrom the evaporator 25 substantially simultaneously. The water from theaccumulator frost passes down through the series .of openings 53 at thebottom of the mixing chamber 32 and fills the trough formed by the lip51 and then flows over the edge 52 of this lip to join the evaporatorcondensate water and eventually down through the pipe 28 into the bottompan 3%. The trough formed by the lip 53. is thus always full ofcondensate water into which the lower edge of the baffle plate 49extends as shown most clearly in FIG. 2. Then during the freezing cyclethis water in the trough freezes to seal the openings 53 and prevent airflow from the mixing chamber 32 through these openings 53 into the airpassage 22. During the next defrost cycle this ice melts.

bodiment of the invention, the invention achieves .a -num-. ber ofimportant advantages. Thus only a single evaporator need be used andthis evaporator coolsboth the freezer chamber and storage chamber air toproper temperatures. Furthermore, air flow is achieved by means of asingle blower and as the conventional blower is rotated in a directionopposite to the conventional direction a greater static presuredifferential is created within the rotary portion of the blower to aidin more efiicient air distribution. A very important advantage of thisstructure is that the storage chambers, the shelves and the food andother articles stored therein aremaintained free of frost. All of thefrost gathers on the evaporator and on the accumulator and these arereadily defrosted in the manner previously described. The structure ofthe invention is relatively inexpensive :to build and is efficient andtrouble-free in its operation.

Having described our invention as related to the embodiment shown in theaccompanying drawings, it is our intention that the invention be notlimited by any of the details of description, unless otherwisespecified, but rather be construed broadly within its spirit and scopeas set out in the accompanying claims.

The embodiments of the inventionin which an'exclusive property orprivilege is claimed are de'fined as follows:

1. Refrigerating apparatus, comprising: -means forming .a relativelylow' temperature first chamber; means forming a relatively hightemperature second chamber; means forminga mixing chamber; means forcirculating a first air stream in a closed circuit through thefirst'chamher and a second airstreamin a closed circuit through thesecond chamber; means directing both an streams ihrough the mixingchamber for inter-mingling therein; and means for cooling only saidfirst air stream at a point downstream from said mixing chamber, themeans for circulating the :second stream being :free .of coolingimeansdownstream from said mixing chamber.

2. Refrigerating apparatuscompri'sing: means forming a relatively lowtemperature first chamber; means forming a relatively high temperaturesecond chamber; means forming a mixing chambcnzmeans forming anairpassage; means for circulating a first air stream in a closed circuitfrom the mixing chamber, through the :air passage and through the firstchamber .into the mixing chamber .anda second air stream in a closedcircuit from the mixing chamber through the second chamber into the:mixing chamber; and means for cooling only ,said lfirst airstrear'n vinsaid air passage, the means for circulating the second (stream beingfree ofcooling means -,downstream:from said mixing chamber.

3. Refrigerating apparatus, comprising: means forming a relatively lowtemperature first chamber; means forming a relatively high temperaturesecond chamber; means forming amixing chamber having a first inletcommunicating with the first chamber and asecond inletcornmunicatingwith the second chamber; air moving means adjacent said mixing chamberhaving an inlet communicating with the mixing chamber, a first outletcommunicating with the first chamber for circulating a first airstreamthere- .through in a closed circuit and :into the mixing chamber and asecond outlet communicating with the secondchambet for circulating asecond air stream therethrough in a closed circuit and into the mixingchamber; and means for cooling only said first air stream at a pointdownstream from said mixing chamber, the means for circulating thesecond stream being free of cooling means downstream from said mixingchamber.

4. Refrigerating apparatus, comprising: means forming a relatively lowtemperature first chamber; means forming a relatively high temperaturesecond chamber; means forming a mixing chamber having a first inletcommunicating with .the first chamber and a second inlet communicatingwith the second chamber; air moving means adjacent said mixing chamberhaving an inlet communicatingtherewith, a first outlet and a secondoutlet; means forming 'a first air passage communicating with said firstoutlet and emptying into the first chamber; means forming a second airpassage adjacent said second chamber communicating with said secondoutlet; means forming an outlet from the second passage to the secondchamber, the air moving means thereby circulating air in a first streamthrough the first passage, first chamber and mixing chamber and in asecond stream through the second passage, second chamber and mixingchamber; and means for cooling the first air stream only in said firstpassage, the second passage being free of cooling means downstream fromsaid mixing chamber.

5. Refrigerating apparatus, comprising: means forming a relatively lowtemperature first chamber; means forming a relatively high temperaturesecond chamber; means forming a mixing chamber having a first inletcommunicating with the first chamber and a second inlet communicatingwith the second chamber; air moving means adjacent said mixing chamberhaving an inlet communicating therewith, a first outlet and a secondoutlet; means forming a first air passage communicating with said firstoutlet and emptying into the first chamber; means forming a second airpassage adjacent said second chamber communicating with said secondoutlet; means forming a plurality of outlets from the second passage tothe second chamber; means in said second chamber for maintaining the airflow from said plurality of outlets substantially parallel, the airmoving means thereby circulating air in a first stream through the firstpassage, first chamber and mixing chamber and in a second stream throughthe second passage, second chamber and mixing chamber; a firstrefrigerant evaporator means in said first passage; and a second refrigerant evaporator means in said mixing chamber, the second passagebeing free of cooling means downstream from said mixing chamber.

6. The apparatus of claim wherein means are provided for directing amajor portion of the total air flow through said first air moving meansoutlet.

7. Refrigerating apparatus, comprising: means forming a relatively lowtemperature first chamber; means forming a relatively high temperaturesecond chamber; means forming a mixing chamber adjacent the top of saidfirst chamber having a first inlet communicating with the first chamberand a second inlet communicating with the second chamber; air movingmeans adjacent said mixing chamber having an inlet communicatingtherewith, a first outlet and a second outlet; means forming a first airpassage extending downwardly from said mixing chamber communicating withsaid first outlet and emptying into the first chamber; means forming asecond air passage adjacent said second chamber communicating with saidsecond outlet; means forming an outlet from the second passage to thesecond chamber, the air moving means thereby circulating air in a firststream through the first passage, first chamber and mixing chamber andin a second stream through the second passage, second chamber and mixingchamber; a first refrigerant evaporator means in said first passage; asecond refrigerant evaporator means in said mixing chamber; meansforming a condensate passage between the mixing chamber and firstpassage for flow therethrough of condensate from said second refrigerantevaporator means; and a trap in said condensate passage to prevent theflow of air therethrough.

8. Refrigerating apparatus, comprising: means forming a relatively lowtemperature first chamber; means forming a relatively high temperaturesecond chamber; means forming a mixing chamber having a first inletcommunicating with the first chamber and a second inlet communicatingwith the second chamber; air moving means adjacent said mixing chamberhaving an inlet communicating with the mixing chamber, a first outletcommunicating with the first chamber for circulating air in a firststream therethrough and into the mixing chamber and a second outletcommunicating with the second chamber for circulating air therethroughin a second stream and into the mixing chamber; means associated withsaid air moving means for directing a major portion of the air from theair moving means through the first outlet, the air moving means having arotor with a plurality of inclined blades circularly arranged andpushing the air outwardly generally radially upon rotation of the rotor;and means for cooling only said first air stream of said first andsecond streams at a point downstream from said mixing chamber.

9. Refrigerating apparatus, comprising: means forming a relatively lowtemperature first chamber; means forming a relatively high temperaturesecond chamber; means forming a mixing chamber adjacent the top of saidfirst chamber having a first inlet communicating with the first chamberand a second inlet communicating with the second chamber; air movingmeans adjacent said mixing chamber having an inlet communicatingtherewith, a first outlet and a second outlet; means forming a first airpassage extending downwardly from said mixing chamber communicating withsaid first outlet and emptying into the first chamber; means forming asecond air passage adjacent said second chamber communicating with saidsecond outlet; means associated with said air moving means for directinga major portion of the air from the air moving means into the firstpassage, the air moving means having a rotor with a plurality ofinclined blades circularly arranged and pushing the air outwardlygenerally radially upon rotation of the rotor; means forming an outletfrom the second passage to the second chamber, the air moving meansthereby circulating air in a first stream through the first passage,first chamber and mixing chamber and in a second stream through thesecond passage, second chamber and mixing chamber; a first refrigerantevaporator means in said first passage; and a second refrigerantevaporator means in said mixing chamber.

10. Refrigerating apparatus, comprising: means forming a relatively lowtemperature first chamber; means forming a relatively high temperaturesecond chamber; means forming a mixing chamber adjacent the top of saidfirst chamber having a first inlet communicating with the first chamberand a second inlet communicating with the second chamber; air movingmeans adjacent said mixing chamber having an inlet communicatingtherewith, a first outlet and a second outlet; means forming a first airpassage extending downwardly from said mixing chamber communicating withsaid first outlet and emptying into the first chamber; means forming asecond air passage adjacent said second chamber communicating with saidsecond outlet; means associated with said air moving means for directinga major portion of the air from the air moving means into the firstpassage, the air moving means having a rotor with a plurality ofinclined blades circularly arranged and pushing the air outwardlygenerally radially upon rotation of the rotor; means forming a pluralityof outlets from the second passage to the second chamber; means in saidsecond chamber for maintaining the air flow from said plurality ofoutlets substantially parallel, the air moving means thereby circulatingair in a first stream through the first passage, first chamber andmixing chamber and in a second stream through the second passage, secondchamber and mixing chamber; a first refrigerant evaporator means in saidfirst passage; a second refrigerant evaporator means in said mixingchamber; means forming a condensate passage between the mixing chamberand first passage for flow therethrough of condensate from said secondrefrigerant evaporator means; and a trap in said condensate passage toprevent the flow of air therethrough.

ll. Refrigerating apparatus, comprising: means forming a relatively lowtemperature first chamber; means forming a relatively high temperaturesecond chamber; a movable closure for said second chamber; means forminga mixing chamber having a first inlet communicating with the firstchamber and a second inlet communicating with the second chamber; airmoving means adjacent said mixing chamber having an inlet communicatingtherewith, a first outlet and a second outlet; means forming a first airpassage communicating with said first outlet and emptying into the firstchamber; means forming a second air passage adjacent said second chambercommunicating with said second outlet; means forming a plurality ofoutlets from the second passage to the second chamber, said plurality ofoutlets and said closure being on opposite sides of the second chamber;means in said second chamber for maintaining the air fiow from saidplurality of outlets substantially parallel toward said closure and thenmerging for flow along said closure, the air moving means therebycirculating air in a first stream through the first passage, firstchamber and mixing chamber and in a second stream through the secondpassage, second chamber and mixing chamber; and means for cooling saidfirst air stream.

12. Refrigerating apparatus, comprising: means forming a relatively lowtemperature first chamber; means forming a relatively high temperaturesecond chamber; means forming a mixing chamber having a first inletcommunicating with the first chamber and a second inlet communicatingwith the second chamber; a blower adjacent said mixing chamber having aninlet communicating therewith, a first outlet and a second outlet; meansforming a first air passage communicating with said first outlet andemptying into the first chamber; means forming a second air passageadjacent said second chamber communicating with said second outlet;means forming an outlet from the second passage to the second chamber,the blower thereby circulating air in a first stream through the firstpassage, first chamber and mixing chamber and in a second stream throughthe second passage, second chamber and mixing chamber; means for coolingsaid first air stream at a point downstream from said mixing chamber;and sub-freezing cooling means associated with said mixing chamber inthe path of air flowing through said second inlet into said mixingchamber.

13. Refrigerating apparatus, comprising: means forming a relatively lowtemperature first chamber; means forming a relatively high temperaturesecond chamber; means forming a mixing chamber adjacent the top of saidfirst chamber having a first inlet communicating with the first chamberand a second inlet communicating with the second chamber; a bloweradjacent said mixing chamber having an inlet communicating therewith, afirst outlet and a second outlet; means forming a first air passageextending downwardly from said mixing chamber communicating with saidfirst outlet and emptying into the first chamber; means forming a secondair passage adjacent said second chamber communicating with said secondoutlet; means forming an outlet from the second passage to the secondchamber, the blower thereby circulating air in a first stream throughthe first passage, first chamber and mixing chamber and in a secondstream through the second passage, second chamber and mixing chamber; afirst refrigerant evaporator means in said first passage; a secondrefrigerant evaporator means in said mixing chamber normally operatingat a sub-freezing temperature and located in the path of air flowingthrough said second inlet into the mixing chamber; means forming acondensate passage between the mixing chamber and first passage for flowtherethrough of condensate from said second refrigerant evaporatormeans; and a trap in said condensate passage to prevent the flow of airtherethrough.

14. Refrigerating apparatus, comprising: means forming a relatively lowtemperature first chamber; means forming a relatively high temperaturesecond chamber; means forming a mixing chamber adjacent the top of saidfirst chamber having a first inlet communicating with the first chamberand a second inlet communicating with the second chamber; a bloweradjacent said mixing chamber having an inlet communicating therewith, a

10 first outlet and a second outlet; means forming a first air passageextending downwardly from said mixing chamber communicating with saidfirst outlet and emptying into the first chamber; means forming a secondair passage adjacent said second chamber communicating with said secondoutlet; means associated with said blower for directing a major portionof the air from the blower into the first passage, the blower having arotor with a plurality of inclined blades circularly arranged andpushing the air outwardly generally radially upon rotation of the rotor;means forming an outlet from the second passage to the second chamber,the blower thereby circulating air in a first stream through the firstpassage, first chamber and mixing chamber and in a second stream throughthe second passage, second chamber and mixing chamber; a firstrefrigerant evaporator means in said first passage; and a secondrefrigerant evaporator means in said mixing chamber normally operatingat a sub-freezing temperature and located in the path of air flowingthrough said second inlet into the mixing chamber.

15. Refrigerating apparatus, comprising: means forming a relatively lowtemperature first chamber; means forming a relatively high temperaturesecond chamber; means forming a mixing chamber; means for circulating afirst air stream in a closed circuit through the first chamber and asecond air stream in a closed circuit through the second chamber; meansdirecting both air streams through the mixing chamber for interminglingtherein; means for cooling only said first air stream at a pointdownstream from said mixing chamber, the means for circulating thesecond stream being free of cooling means downstream from said mixingchamber; and additional means for cooling said mixing chamber.

16. Refrigerating apparatus, comprising: means forming a relatively lowtemperature first chamber; means forming a relatively high temperaturesecond chamber; means forming a mixing chamber having a first inletcommunicating with the first chamber and a second inlet communicatingwith the second chamber; air moving means adjacent said mixing chamberhaving an inlet communicating with the mixing chamber, a first outletcommunicating with the first chamber for circulating a first air streamtherethrough in a closed circuit and into the mixing chamber and asecond outlet communicating with the second chamber for circulating asecond air stream therethrough in a closed circuit and into the mixingchamber; means for cooling only said first air stream at a pointdownstream from said mixing chamber, the means for circulating thesecond stream being free of cooling means downstream from said mixingchamber; and means for directing a major portion of the air from saidmixing chamber through said first outlet.

17. Refrigerating apparatus, comprising: means forming a relatively lowtemperature first chamber; means forming a relatively high temperaturesecond chamber; means forming a mixing chamber; means for circulating afirst air stream in a closed circuit through the first chamber and asecond air stream in a closed circuit through the second chamber, saidair circulating means providing a larger volume rate of flow in saidfirst stream than in said second stream; means directing both airstreams through the mixing chamber for intermingling therein; and meansfor cooling only said first air stream at a point down stream from saidmixing chamber, the means for circulating the second stream being freeof cooling means downstream from said mixing chamber.

References Cited in the file of this patent UNITED STATES PATENTS (Qtherreferences on followin .a e)

a l g 11 UNITED STATES PATENTS Hoffman Aug. 12, 1947 Pabst Oct. 14, 1952Brinkoeter Oct. 14, 1952 Strang Mar. 10, 1953 5 12 Weber Mar. 17, 1953Murphy Dec. 9, 1958 Mann Oct. 6, 1959 Mann Nov. 17, 1959

